Many devices, electronic or otherwise, have been made for the purpose of detecting the presence of water/glycol in an oil system. The presence of water/glycol in an oil system is significant not only because it is a contaminant, but also because its presence is often an indication that coolant is leaking due to system damage. The detection of engine or pump damage at the earliest possible stage can significantly reduce the cost of repair. This is especially important on very expensive heavy machinery such as is used in construction or mining.
U.S. Pat. No. 4,624,779, issued Nov. 25, 1986, and U.S. Pat. No. 4,995,992, issued Feb. 26, 1991, both to Irwin E. Hurner, disclose devices for filtering contaminants and water from fuel. These devices separate water by use of a microscreen and accumulate the separated water in a chamber to be drained away as necessary. U.S. Pat. No. 4,745,893, issued May 24, 1988, to Atherton et al. discloses an oil level sensor which includes a probe having a pair of electrodes forming a capacitor. This device digitally senses oil level by sensing the difference in capacitance between oil and air. The above-identified patents should be carefully studied and considered for placing the present invention in proper context.